Regarding pay, I dunno. Based on quotes from this[1] article, the pay scale seems to cap out at GS15 Step 10 which is ~132k. Now obviously this is still a lot of money but if I'm reading between the lines of his quotes right, this is the most an engineer can make w/ USDS without bumping up to SES (Senior Executive Service) levels. Not to say that's substantively less than industry salaries, but they definitely are paying government salaries (by definition).
As far as dissolution, I'm talking more from the perspective of attracting & retaining top talent. With a private sector startup, you trade job security for potentially out-sized payoff. But here... Anyway, point being I think the risks should be articulated well.
[1] http://fcw.com/articles/2014/10/27/red-tape-holding-back-hir...